1. Field of the Invention
The present invention relates generally to a vacuum cleaner, and more particularly, it relates to a cyclone-type dust-collecting apparatus for use in a vacuum cleaner capable of separating various contaminants (hereinafter collectively called xe2x80x98dustxe2x80x99) from an air drawn through a suction portion of the vacuum cleaner by using a centrifugal force of a whirling air current it causes from the drawn air.
2. Description of the Background Art
One example of a cyclone-type dust collecting apparatus for use in vacuum cleaner is disclosed by commonly assigned U.S. Pat. No. 6,195,835, the structure of which is schematically shown in the accompanying drawings FIGS. 1 through 4.
As shown in FIGS. 1 through 4, the cyclone-type dust collecting apparatus for use in a vacuum cleaner generally includes a cyclone body 20, a dust-collecting chamber 30 and a grill assembly 40.
The cyclone body 20 is divided into an upper body 21 and a lower body 22, which are connected to each other by a plurality of screws 23. The lower body 22 has an inflow pipe 24 connected to an extension pipe 1a itself connected to a suction port of the vacuum cleaner (not shown), and an inflow port 25 in fluid communication with the inflow air pipe 24. The upper body 21 has an outflow pipe 26 connected to the extension pipe 1b extending toward a body of the cleaner, and an outflow port 27 in fluid communication with the outflow pipe 26. Dust-laden air is drawn into the cleaner through the suction port in a diagonal direction with respect to the cyclone body 20, thereby forming a cyclonic whirling air current inside of the cyclone body 20. The centrifugal force of the whirling air current causes the dust to be separated from the air.
The dust collecting chamber 30 is removably connected to the cyclone body 20, functioning to generate a whirling air current in cooperation with the cyclone body 20, and also to collect the dust separated from the air by the whirling air current.
The grill assembly 40 is mounted at the outflow port 27 of the cyclone body 20, preventing reverse flow of the dust that is collected in the dust-collecting chamber 30, through the outflow port 27. The grill assembly 40 has a grill body 41, a grill portion 42 formed along the outer circumference of the grill body 41 to define a passage in fluid communication with the outflow port 27, and a dust reverse flow preventing portion 43, in the shape of a cone and formed at a lower end of the grill body 41. An upper portion 41a of the grill body 41 is supported between the upper and lower bodies 21, 22 of the cyclone body 20 so that the grill assembly 40 can be mounted at the outflow port 27 of the cyclone body 20. The grill portion 42 is formed by penetrating a plurality of fine holes along the outer circumference of the grill body 41.
In the cyclone-type dust-collecting apparatus for use in the vacuum cleaner, the dust-laden air is drawn by the suction force generated at the suction port of the cleaner and directed into the cyclone body 20 through the inflow port 25. The air flowing into the cyclone body 20 in a diagonal direction descends in the dust-collecting chamber 30 in a whirling current (curved arrow-headed solid line of FIG. 1). During this process, dust is separated from the air by the centrifugal force of the whirling current, and is collected in the dust-collecting chamber 30.
Upturning air from the bottom of the dust-collecting chamber 30 is discharged to the cleaner body via the grill portion 42 of the grill assembly 40, the outflow port 27 and the outflow pipe 26 (xe2x80x94shown by phantom arrow of FIG. 1). Some dust still remaining in the upturning air current of the dust-collecting chamber 30 is blocked by the dust reverse flow preventing portion 43 extending toward the whirling air current. Dust still remaining in the air, even after the dust reverse flow preventing portion 43 is discharged through the grill portion 42 of the grill assembly 40, becomes entrained in the discharged air. Among such dust, some dust particles, which are larger than the fine holes of the grill portion 42, are blocked by the grill portion 42 and are returned to the whirling current.
The dust-laden air drawn into the cyclone body 20 can contain very fine dust particles, and as these are very light, the fine dust particles are rarely separated by the centrifugal force of the whirling air. Accordingly, the fine dust particles still remain in the air, and eventually block the grill portion 42 as the air is discharged through the grill portion 42. As the grill portion 42 is blocked, suction force is from the motor is reduced, and thus, the suction efficiency deteriorates.
Usually, such dust at the grill portion 42 remains even after the cleaning operation, causing the same or decreased suction efficiency in the next cleaning operation. Accordingly, such dust particles have to be dealt with on a regular basis, which means expending labor and time have for device cleaning or maintenance.
In the conventional cyclone-type dust-collecting apparatus, as the grill assembly 40 is supported between the upper and lower bodies 21, 22 of the cyclone body 20, it is difficult for a user to remove the grill assembly 40. Accordingly, cleaning or repairing of the grill assembly 40 is a complicated operation. Also, while wiping the grill assembly 40 after it has been removed, the user usually experiences discomfort since he/she has the dust on his/her hands. In addition, the dust normally falls in an area around the user, thereby polluting the surrounding area. Yet another problem is that the user usually requires many time and labor to clean the grill assembly 40 completely. All these problems will definitely result in a device that is undesirable to a purchaser.
Still another problem of a vacuum cleaner employing such a conventional cyclone-type dust-collecting apparatus is that the vacuum cleaner is difficult to use and handle. More specifically, as shown in FIG. 3, the user cleans the required area with his/her hands holding a grip G provided adjacent the extension pipe 1b on the side toward the cleaner body. It is very hard for the user to dean the area while moving the suction port E, connected with the cyclone-type dust-collecting apparatus, only with one hand. Automatically, the user usually holds the extension pipe with his/her other hand as shown in FIG. 3, which is inconvenient. Because there is no separate handle or part attached to the dust-collecting apparatus to hold it with, it is usually difficult for the user to perform the cleaning operation or to handle the cleaner. Reference character CB in FIG. 3 denotes the cleaner body and a cyclone-type dust-collecting apparatus S is mounted between the extension pipes 1a, 1b. 
In the cyclone-type dust-collecting apparatus as described above, cleaning efficiency depends on the whirling air current generated inside of the cyclone body 20. The whirling air current with stable directionality can contribute to superior cleaning efficiency. In the conventional cyclone-type dust-collecting apparatus, however, airflow of directionalities may be different from those that are desired. The desired air current, indicated by an arrow A in FIG. 4, is the flow moving along an inner circumference 22a of the lower body 22 of the cyclone body 20. Here, airflow of different and undesirable directionalities are indicated by the arrows B and C in FIG. 4. Most of time, the air currents B and C would eventually follow the desired direction A. The problem is that during at least a portion of the operation, unstable currents moving in different directions arise that interfere with the desired air flow and thus cause a reduction in efficiency.
Accordingly, it is an object of the present invention to provide a cyclone-type dust-collecting apparatus for use in a vacuum cleaner, thereby increasing the ease in cleaning and repairing a grill assembly, and further, in using and handling the vacuum cleaner.
Another object is to provide a cyclone-type dust-collecting apparatus for use in a vacuum cleaner, having an enhanced efficiency by maximizing stability and directionality of a whirling current generated in a cyclone body.
The above-mentioned objects are accomplished by a cyclone-type dust-collecting apparatus for use in a vacuum cleaner according to the present invention, including a cyclone body having an inflow port and an outflow port, the cyclone body being capable of forming a whirling air current from dust-laden air drawn into the vacuum cleaner through the inflow port; a dust collecting chamber removably connected with the cyclone body for collecting dust separated from the drawn air in the whirling air current; and a grill assembly disposed at the outflow port of the cyclone body for preventing a reverse flow of the dust through the outflow port of the cyclone body. The grill assembly includes a first grill member having a supporting portion supported on the outflow port of the cyclone body; a second grill member removably connected to a lower opening of the first grill member; and a grill portion defining a passage in fluid communication with the outflow port in an outer circumference of the second grill member.
The second grill member having the grill portion, i.e., the portion that is easily contaminated by the dust, is removably screwed to the first grill member that is secured to the cyclone body. Accordingly, the user can remove the dust over the grill portion after simply separating the second grill member. As the user can clean the grill portion of the grill assembly in a convenient way, cleaner maintenance and care can be performed easily.
According to a preferred embodiment of the present invention, the first grill member comprises a female-screw portion formed on an inner circumference of the lower opening, and the second grill member comprises a male-screw portion formed on an outer circumference of upper portion corresponding to the female-screw portion.
The grill portion is formed by fitting a mesh filter into the second grill member, the mesh filter comprising a plurality of fine holes, and the second grill member comprising a plurality of window-shaped openings formed in the outer circumference in a radial direction.
The mesh filter comprises: a filter frame comprising an upper ring, a lower ring, and two or more ribs connecting upper and lower rings; and a net insert-molded into the filter frame so as to be placed in openings partitioned by the ribs of the filter frame.
The filter frame may be formed of a plastic, and upper and lower rings of the filter frame are vapor-deposited onto a corresponding portion of the second grill member so that the filter frame is inserted in the second grill member, thereby constituting the mesh filter.
The filter frame may comprise rubber, and produce an interference-fit in the second grill member, thereby constituting the mesh filter.
The grill portion may be formed by direct boring a plurality of fine holes in the outer circumference of the second grill member.
According to another preferred embodiment of the present invention, the grill assembly comprises a dust reverse flow preventing member disposed at the lower opening of the second grill member for deflecting the dust entrained in the upwardly directed air current of the dust collecting chamber.
The dust reverse flow preventing member comprises: a cylinder press fit through the lower opening of the second grill member, and comprising upper and lower supporting portions having two or more ribs; a shaft supported by upper and lower supporting portions; and a plate connected to an end of the shaft, disposed at a predetermined distance from a lower end of he second grill member.
The cylinder comprises a spiral guide formed therein for guiding a flow of air being discharged therethrough. The cylinder and the plate may be formed of rubber.
The plate may comprise a conical or frusto-conical shape.
According to yet another preferred embodiment of the present invention, the cyclone body comprises a secondary handle protruding from an extension pipe of the vacuum cleaner to enable a user to grip the extension pipe. The user can perform the cleaning operation conveniently, with one hand holding the grip of the extension pipe and the other hand holding the secondary handle.
The cyclone body may comprise upper and lower bodies which are separately formed and mate with each other, and the secondary handle may comprise a pair of handle portions having symmetrical shapes formed on upper and lower bodies and mated with each other.
Another object is accomplished by the cyclone body comprising a guiding surface formed at a sidewall of the inflow port, for guiding the flow of air drawn in through the inflow port and thereby improving the directionality of the drawn air, the guiding surface being formed at a predetermined radius of curvature.
Stability and directionality of the whirling air current in the cyclone body are improved, and efficiency in operation and reverse flow prevention can be expected.
The radius of curvature of the guiding surface is smaller than the radius of curvature of the inner circumference of the cyclone body.